In order to provide a wider working width and yet an acceptable transport, width, agricultural implements commonly include a plurality of foldable frame sections. The foldable frame sections are pivotally coupled to one another at a pivot location so that the agricultural implement can more closely follow the contour of the ground and yet fold for transport. The frame sections support a plurality of ground-engaging tools (e.g., disk gang assemblies), which are drawn through the soil.
As the ground-engaging tools are drawn through the soil, forces are applied to the ground-engaging tools in a rearward, an upward, and an inward direction. These forces are often referred to as draft force, penetration force, and thrust force, respectively. Since the thrust force is applied below the pivot location, there is a moment or twist load applied at the pivot location. The twist load can cause each frame section to drive deep into the soil on one end while driving shallow at the other end. This non-uniform depth across a frame section can create streaks in a field, uneven seed bed preparation, and uneven volunteer vegetation growth.
Often, the hinge axis is lowered or weight is added to the frame sections near the pivot location to create a more uniform depth. Alternatively, the frame sections are locked together at the pivot location. A hydraulic system for controlling weight transfer between the frame sections is illustrated in commonly assigned U.S. Pat. No. 4,630,526.